Medical devices and delivery systems for delivering medical devices

ABSTRACT

Medical devices and delivery systems for delivering medical devices to a target location within a subject. In some embodiments the medical devices can be locked in a fully deployed and locked configuration. In some embodiments the delivery systems are configured with a single actuator to control the movement of multiple components of the delivery system. In some embodiments the actuator controls the independent and dependent movement of multiple components of the delivery system.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.14/586,791, filed Dec. 30, 2014, now U.S. Pat. No. 9,387,076, which is acontinuation of U.S. application Ser. No. 12/578,447, filed Oct. 13,2009, now U.S. Pat. No. 8,951,299, which claims priority under 35 U.S.C.sctn. 119 to U.S. Provisional Patent Application Nos. 61/104,509, filedOct. 10, 2008; and 61/151,814, filed Feb. 11, 2009; which applicationsare incorporated by reference in their entirety.

This application is related to the following patent applications, all ofwhich are incorporated by reference herein: U.S. patent application Ser.No. 10/746,240, filed Dec. 23, 2003 (U.S. Patent Publication No.2005/1237687); U.S. patent application Ser. No. 10/972,287, filed Oct.21, 2004 (U.S. Patent Publication No. 2005/0137698); U.S. patentapplication Ser. No. 10/982,692, filed Nov. 5, 2004 (U.S. PatentPublication No. 2005/0137699); U.S. patent application Ser. No.11/706,549, filed Feb. 14, 2007 (U.S. Patent Publication No.2007/0203503); U.S. Provisional Patent Application No. 61/104,509, filedNov. 10, 2008; U.S. patent application Ser. No. 11/274,889, filed Nov.14, 2005 (U.S. Patent Publication No. 2007/0112355); U.S. patentapplication Ser. No. 10/870,340, filed Jun. 16, 2004 (U.S. PatentPublication No. 2005/0283231); and U.S. patent application Ser. No.11/314,969, filed Dec. 20, 2005 (U.S. Patent Publication No.2007/0118214).

BACKGROUND OF THE INVENTION

Implantable medical devices can be delivered to a target location withina patient and implanted therein. For example, endoluminal deliverytechniques are well known. The delivery system typically includes asheath and/or a catheter through which the implant is delivered to thetarget location. The implant is generally deployed from the sheath orcatheter at the target location. Some implantable devices are completelyself-expanding; they self-expand when released from the sheath orcatheter and do not require any further expansion after theself-expanding step. The self-expansion can occur by proximallyretracting the sheath or catheter, by pushing the implantable devicefrom the sheath or catheter, or a combination thereof. Some implantabledevices, however, are configured and adapted to be actuated during orafter the self-expansion step. Exemplary replacement heart valves whichcan be actuated after a self-expansion step can be found described inco-pending application Ser. No. 10/982,388, filed Nov. 5, 2004, andapplication Ser. No. 10/746,120, filed Dec. 23, 2003, the disclosures ofwhich are hereby incorporated by reference herein. It may beadvantageous to lock an expandable medical device in a fully deployedand locked configuration to secure the device in the deployed.

During the delivery process the medical device can be actuated by thedelivery system using one or more actuators. For example, an actuator(e.g., in the form of a knob on a handle of the delivery system) may beactuated (e.g., turned) to cause a component of the delivery system tomove relative to another component in the delivery system or relative tothe implantable device, or both. It is generally desirable to make thedelivery process as easy as possible for the physician, reduce the timeneeded to complete the procedure, and reduce the mechanical complexityof the delivery system. In some delivery procedures, multiple componentsof the delivery system need to be actuated to deploy the implant. It mayalso be necessary to ensure that multiple steps are carried out in acertain order. What are needed are delivery systems which can simplifythe deployment procedure of the medical device and/or ensure thatmultiple steps are performed in a certain order.

SUMMARY OF THE INVENTION

One aspect of the disclosure describes a medical device system,including a delivery system comprising a housing disposed external to asubject, wherein the housing comprises an actuator, wherein the deliverysystem is configured and arranged such that the actuator is adapted tomove a first delivery system component independently of a seconddelivery system component, and wherein the delivery system is furtherconfigured and arranged such that actuator is also adapted to move thesecond delivery system component independently of the first deliverysystem component.

In some embodiments the delivery system is further configured andarranged such that the actuator is further adapted to actuate the firstdelivery system component and the second delivery system componentsimultaneously, and is some instances at different rates when actuatingthem simultaneously.

In some embodiments the delivery system is configured such thatactuation of the actuator moves the first and second delivery systemcomponents in the same direction. In some embodiments the deliverysystem is configured such that actuation of the actuator actuates thefirst and second delivery system components in a specific sequence.

In some embodiments the actuator is a single actuator element, andwherein the actuator is configured such that actuation of the actuatorin a single type of motion causes both the actuation of the firstdelivery system component independent of the second delivery systemcomponent and the actuation of the second delivery system componentindependent of the first delivery system component.

In some embodiments the first delivery system component is a deliverysheath, and wherein the medical device system comprises a medical deviceadapted to be percutaneously delivered to a target location in a patientthrough the delivery sheath, and wherein the actuator is adapted to movethe delivery sheath independently of and prior to the independentmovement of the second delivery system component. The second deliverysystem component can be reversibly coupled to a portion of the medicaldevice. The actuator can be adapted to independently move both thesheath and the second delivery component proximally when actuated.Actuation of the actuator can be configured to proximally retract thesheath to allow the medical device to expand, and wherein furtheractuation of the actuator retracts the second delivery system componentproximally.

In some embodiments the delivery system and actuator are configured suchthat movement of the actuator in a singular type of motion, such asrotation in a single direction, moves the first delivery systemcomponent independently of a second delivery system component and movesthe second delivery system component independently of the first deliverysystem component. The singular type of motion can move the firstdelivery system component independently of a second delivery systemcomponent and moves the second delivery system component independentlyof the first delivery system component without any intervening actuationsteps being performed between the independent movement of the firstdelivery system component and the independent movement of the seconddelivery system component.

One aspect of the disclosure is a method of using a delivery system todeploy a medical device in a patient. The method includes providing adelivery system comprising a housing disposed external to the patient,wherein the housing comprises an actuator, actuating the actuator tomove a first delivery system component independently of a seconddelivery system component, and actuating the actuator to move the seconddelivery system component independently of the first delivery systemcomponent.

In some embodiments the further comprises actuating the actuator to movethe first and second delivery system components simultaneously. In someembodiments actuating the actuator comprises actuating the actuator in asingular type of motion to move the first and second delivery systemcomponents independently of one another, as well as to move the firstand second delivery system components simultaneously. Actuating theactuator can move the first and second delivery system components atdifferent rates at least during a portion of the time they are beingmoved simultaneously.

In some embodiments actuating the actuator moves the first and seconddelivery system components in the same direction. In some embodimentsactuating the actuator moves the first and second delivery systemcomponents in a specific sequence.

In some embodiments actuating the actuator comprises actuating theactuator in a singular type of motion, such as rotation in a singledirection, to move both the first and second delivery system componentsindependently of one another.

In some embodiments the first delivery system component is a deliverysheath, and wherein actuating the actuator comprises moving the deliverysheath in a proximal direction independently of and prior to theindependent movement of the second delivery system component. The seconddelivery system component can be reversibly coupled to a medicalimplant, and wherein actuation of the second delivery system componentindependently moves the second delivery system component in a proximaldirection independently of and subsequent to the proximal movement ofthe delivery sheath.

In some embodiments moving the first and second delivery systemcomponents comprises moving the first and second delivery systemcomponents proximally.

In some embodiments actuating the actuator to move the first deliverysystem component comprises moving a delivery sheath proximally to allowthe medical device to expand.

One aspect of the disclosure is a delivery system for deploying amedical device in a patient. The system includes a delivery sheath, adelivery catheter adapted to be disposed within the sheath and movablerelative to the sheath, a coupling member adapted to be reversiblycoupled to a portion of a medical device, wherein the medical device isadapted to be percutaneously delivered to a target location in a patientthrough the delivery sheath, wherein the delivery sheath is adapted tobe moved relative to the medical device to release the medical devicefrom the sheath, and a sheathing assist element, at least a portion ofwhich is disposed between a distal end of the sheath and a proximalportion of the medical device when the delivery sheath is sheathing atleast the proximal portion of the medical device.

In some embodiments a proximal portion of the sheathing assist elementis attached to a distal region of the delivery catheter. In someembodiments a proximal end of the coupling member is attached to thedistal region of the delivery catheter.

In some embodiments a proximal end of the sheathing assist element isattached to a distal region of the delivery catheter, and wherein aproximal end of the coupling member is attached to the distal region ofthe delivery catheter, and wherein the sheathing assist element isradially outward relative to the coupling member.

In some embodiments the sheathing assist element comprises a pluralityof looped elements, wherein a first one of the looped elements has alength that is different than the length of a second one of the loopedelements.

In some embodiments the medical device comprises a braided element, andwherein the sheathing assist element comprises a plurality of sheathingassist elements, wherein a first of the plurality of sheathing assistelements is disposed radially outward of a proximal end of the braidedelement when the sheath is sheathing the braided element, and wherein asecond of the plurality of sheathing assist elements extends through thebraided element.

One aspect of the disclosure is a method of sheathing a medical devicewithin a delivery sheath. The method includes positioning a sheathingassist element between a portion of an expandable medical device and adelivery sheath, and moving the delivery sheath distally relative to thesheathing assist element and the medical device to assist in thecollapse of at least a portion of the expandable medical device withinthe delivery sheath.

In some embodiments the positioning step comprises positioning thesheathing assist element between at least a proximal end of theexpandable medical device and the distal end of the delivery sheath toreduce the likelihood that the distal end of the sheath will get caughton the proximal end of the medical device as the delivery sheath ismoved distally relative to the sheathing assist element.

In some embodiment the delivery system further comprises a couplingmember, the method further comprising maintaining a reversible couplingbetween the coupling member and the medical device, wherein positioningthe sheathing assist element comprises positioning the sheathing assistelement radially outward relative to the coupling member.

In some embodiments moving the delivery sheath distally relative to thesheathing assist element causes a radially inward force to be appliedfrom the sheathing assist element to the portion of the expandablemedical device.

INCORPORATION BY REFERENCE

All publications and patent applications mentioned in this specificationare hereby incorporated by reference herein to the same extent as ifeach individual publication or patent application was specifically andindividually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIG. 1A shows an exemplary replacement heart valve in a deployed andlocked configuration.

FIG. 1B shows an exemplary replacement heart valve in a collapsed anddelivery.

FIG. 2A illustrates an exemplary medical device delivery systemreversibly coupled to a medical device, wherein the medical device is ina collapsed configuration.

FIG. 2B shows an exemplary medical device delivery system reversiblycoupled to a medical device, wherein the medical device is in a deployedand locked configuration.

FIGS. 3A-3G illustrate an exemplary medical device deployment andlocking procedure.

FIG. 4 shows an exemplary replacement heart valve reversibly coupled toa portion of a delivery system.

FIGS. 5A-5E show an exemplary lock and release mechanism for a medicaldevice.

FIGS. 6A and 6B show an exemplary reversible coupling mechanism betweena delivery system and a medical device.

FIGS. 7A-7D shows an exemplary lock and release mechanism of a medicaldevice.

FIGS. 8A-8G shows an exemplary lock and release mechanism of a medicaldevice.

FIG. 9 shows an exemplary reversible coupling mechanism between adelivery system and a medical device.

FIG. 10 shows an exemplary reversible coupling mechanism between adelivery system and a medical device.

FIGS. 11A-11D show an exemplary lock and release mechanism of a medicaldevice.

FIGS. 12A-12C show an exemplary lock and release mechanism of a medicaldevice.

FIGS. 13-14E show an exemplary lock and release mechanism of a medicaldevice.

FIGS. 15A-16B show an exemplary lock and release mechanism of a medicaldevice.

FIGS. 17A-17D illustrate a portion of an exemplary delivery system inwhich a single handle actuation element can move two different deliverysystem components independently of one another.

FIG. 18A-18D illustrate an varying pitch design to vary the rate oftravel of an actuation element.

FIG. 19 illustrates an exemplary barrel-cam design to control the rateof movement of delivery system components.

FIGS. 20A-20C illustrate a portion of an exemplary delivery system inwhich a single handle actuation element can move two different deliverysystem components independently of one another.

FIGS. 21-22 illustrate exemplary designs for decoupling the motion ofthe rods and outer sheath.

FIGS. 23A-23C illustrate actuating a second actuator to control movementof different portions of the medical device delivery process.

FIGS. 24-41 illustrate a variety of medical device sheathing assistelements.

DESCRIPTION OF THE INVENTION

The present disclosure describes medical devices and delivery systemsfor delivering medical devices to a target location in a subject. Themedical devices can be implantable or they can be adapted to betemporarily positioned within the subject. The delivery systems can beadapted to deliver a wide variety of suitable medical devices to atarget location in a subject, but in some embodiments are configured forminimally invasive delivery procedures, such as endovascular procedures.In some embodiments the medical device is a replacement heart valve(e.g., a replacement aortic heart valve), and the delivery system isconfigured to deliver the replacement heart valve endovascularly toreplace the functionality of the subject's native heart valve.

FIGS. 1A and 1B show replacement heart valve 10 including anchoringelement 12, shown comprising a braided material, and replacement valveleaflets 14 (not shown in FIG. 1B for clarity). Replacement heart valve10 also includes three first locking members 16, also referred to hereinas posts, and three second locking members 18, also referred to hereinas buckles. Three posts and three buckles are shown, each post beingassociated with one of the buckles. FIG. 1A shows anchoring element 12,also referred to herein an anchor, in a fully deployed configuration inwhich anchoring element 12 is locked and maintained in the deployedconfiguration by the locking interaction between first locking members16 and second locking members 18. FIG. 1B shows replacement heart valve10 in a collapsed delivery configuration in which the replacement heartvalve is delivered within a delivery system to a target location withinthe subject (delivery system not shown).

In this embodiment valve leaflets 14 are attached to posts 16 at thevalve's three commissures. Posts 16 therefore support the valve withinthe anchoring element. The posts and buckles (or other suitable firstand second locking members) are both coupled to the anchor. When theanchoring element 12 is in the collapsed configuration as shown in FIG.1B, each locking element of posts 16 which is configured to lock with acorresponding locking element of buckles 28 is located distally relativeto the locking element of the buckle to which is it to adapted to belocked. Stated alternatively, the locking elements of the buckles whichare configured to lock to the locking elements of the posts are locatedproximally to the locking elements of the posts in the deliveryconfiguration.

FIGS. 2A and 2B illustrate an exemplary embodiment of a delivery system100 and components thereof which can be used to deliver and deploy amedical device at a target location in a subject. Delivery system 100includes handle 120, sheath 110, catheter 108 disposed with sheath 110,and actuation elements 106A and 106B which are reversibly coupled toreplacement heart valve 10. In FIG. 2A, heart valve 10 is in a collapseddelivery configuration (also shown in FIG. 1B) within sheath 110.Delivery system 100 also includes guidewire G and nosecone 102. In someembodiments catheter 108 has central lumen 109 and a plurality ofcircumferentially disposed lumens Lu.

In FIGS. 2A and 2B, the plurality of actuation elements 106A are shownreversibly coupled to a proximal region of anchoring element 12.Specifically, actuation elements 106A are reversibly coupled to theproximal end of the anchoring element 12 via a reversible couplingmechanism. Actuation elements 106B are reversibly coupled to a region ofthe replacement heart valve distal to the proximal end of the anchoringelement. Specifically, actuation elements 106B are shown reversiblycoupled to posts 16 via a reversible coupling mechanism. Details of thisand similar embodiments can be found in U.S. Patent Publication Nos.2005/0137686 and 2005/0143809, the disclosures of which are incorporatedby reference herein.

In the embodiments shown in FIG. 1A-2B, the anchoring element comprisesa braided material, such as nitinol, and is formed of one or morestrands of material. In one embodiment the anchoring element 12 isformed of a shape memory material and is heat set in a self-expandedconfiguration, such that when the anchoring element is deployed from thesheath of the delivery system, the braid will begin to naturally beginto shorten and expand from the collapsed delivery configuration to thememory self-expanded configuration. The self-expanded configuration canbe thought of as an at-rest or partially deployed configuration, and isdescribed in more detail in U.S. Patent Publication Nos. 2005/0137686and 2005/0143809. Once the anchoring element has expanded to thepartially deployed configuration, at least one of the actuators 106A and106B is actuated via an actuator on a handle disposed external to thepatient. As is described in more detail in U.S. Patent Publication Nos.2005/0137686 and 2005/0143809, actuators 106B can be actuated in theproximal direction relative to the actuation elements 106A, whichapplies a proximally directed force to the posts, which applies aproximally directed force to a distal region of the anchoring element.Actuators 106A can, alternatively or in addition to the proximallydirected force, be actuated in a distal direction to apply a distallydirected force on a proximal region of the anchoring element. Theaxially directed forces actively foreshorten the anchoring element,moving the posts closer to the buckles until the posts and buckles locktogether to lock the anchoring element in a fully deployed and lockedconfiguration. The locked configuration is therefore shorter than thepartially-deployed configuration.

FIGS. 3A-3G illustrate an exemplary method of delivering a replacementaortic heart valve in a delivery configuration and deploying it from adelivery sheath to a fully deployed and locked configuration. In thisembodiment actuation elements 106B are reversibly coupled to the postsof the replacement valve, but actuation elements 106A, which may also bereferred to herein as “fingers,” are reversibly coupled to the buckles.There are three actuation elements 106A reversibly coupled to the threebuckles, and there are three actuation elements 106B reversibly coupledto the three posts. As seen in FIG. 3A, replacement valve 10 isdelivered in a collapsed delivery configuration within sheath 110 in aretrograde fashion through aorta A over guidewire G and placed across apatient's aortic valve using known percutaneous techniques.

Once sheath 110 is positioned across the native valve as shown in FIG.3A, sheath 110 is retracted proximally relative to the replacement valveusing an actuator on the delivery system handle which is disposedexternal to the patient (examples of which are described in detailbelow). As the sheath is withdrawn, as seen in FIG. 3B, the distalportion of anchoring element 12 begins to self-expand due to thematerial properties of the anchoring element. The anchoring element canhave a memory self-expanded configuration such that as the sheath iswithdrawn the anchor begins to self-expand, or return to its memoryconfiguration. As the sheath continues to be retracted proximally, theanchoring element continues to self-expand, as shown in FIGS. 3C and 3D.In FIG. 3E the sheath has been retracted proximally such that the distalend of the sheath is disposed proximal to the distal end of fingers106A. In FIG. 3E the sheath is not retracted far enough proximally toallow the fingers to self-expand. As such, although the anchoringelement is completely out of the sheath, the proximal end of the anchordoes not expand towards its memory configuration. Only after the sheathhas been retracted past the distal end of catheter 108 can the fingersfully self-expand, as is shown in FIG. 3F. This allows the proximal endof the anchoring element to expand. 100601 The anchoring element is thenactively foreshortened (and potentially further expanded) to the fullydeployed and locked configuration shown in FIG. 3G by the application ofaxially directed forces (proximally and distally directed). To activelyforeshorten the anchoring element, a proximally directed force isapplied to posts via actuation elements 106B (not shown in FIGS. 3A-3Gbut which are coupled to the posts), and/or a distally directed force isapplied to buckles via actuation elements 106A. In one embodiment aproximally directed force is applied to posts through actuation elements106B, and fingers 106A are held in position to apply a distally directedforce to the buckles. This active foreshortening causes the posts andbuckles to move axially closer to one another until they lock together,which maintains the anchoring element in a fully deployed and lockedconfiguration in FIG. 3G. The actuation elements 106A and 106B are thenuncoupled released from the buckles and posts, respectively, and thedelivery system is then removed from the subject. The details ofexemplary locking processes and release processes are described indetail below. Additional details of delivery, deployment, locking, andrelease processes that may be incorporated into this and otherembodiments can be found in U.S. Patent Publication No. 2005/0137699,filed Nov. 5, 2004, U.S. Patent Publication No. 2007/0203503, filed Feb.14, 2007, and U.S. Patent Publication No. 2005/0137697, filed Nov. 21,2004, each of which is incorporated by reference herein.

FIG. 4 shows replacement heart valve 10 and a distal portion of thedelivery system, including catheter 208, which were described inreference to FIGS. 3A-3G. Heart valve 10 is in a fully deployed andlocked configuration, with actuation elements 206A (“fingers”) and 206Bstill reversibly coupled to buckles 18 and posts 16, respectively. Theconfiguration and arrangement in FIG. 4 is therefore similar to thatshown in FIG. 3G. The commissure portions of leaflets 14 are affixed tothe three posts 16, while posts 16 are moveably coupled to anchoringelement 12 (e.g., via sutures or wires) at a location distal to theproximal end of anchoring element 12. Replacement heart valve 10 alsoincludes buckles 18 (three are shown) which are affixed (but may bemoveably coupled to the anchor similar to the posts) to anchor 12 (e.g.,via wires or sutures) at a proximal region of anchor 12. In FIG. 4, theactuation elements 206B are reversibly coupled to posts 16, whileactuation elements 206A are reversibly coupled to buckles 18. Thedelivery system also includes three actuator retaining elements 210,each of which are adapted to receive therein an actuation element 206Band an actuation element 206A. Actuation elements 206A are shownattached at their proximal end to the distal end of catheter 208, whileactuation elements 206B are configured and arranged to move axiallywithin catheter 208. Actuation elements 206B therefore are configuredand arranged to move axially with respect to actuation elements 206A aswell. Fingers 206A and actuation elements 206B are maintained closelyspaced to one another (at least while the delivery system is coupled tothe replacement valve) with actuator retaining elements 210. Retainingelements 210 have a lumen therein in which fingers 206A are disposed andthrough which the actuation elements 206B can be actuated axially.Fingers 206A are shown disposed radially outward relative to theactuation elements 206B, which are shown as generally cylindrical rods.The replacement heart valve in FIG. 4 has not been released from thedelivery system.

FIGS. 5A-5E illustrate the process of uncoupling the delivery systemfrom the heart valve shown in FIG. 4 (anchoring element is not shown).In FIG. 5A post 16 has an elongated locking portion 17 which is adaptedto be pulled into an internal channel within buckle 18. Locking portion17 of post 16 has a locking element in the shape of a groove which isadapted to receive a tooth on the buckle 18. As the post is pulled intothe buckle, the tooth on the buckle will engage the groove on the postand lock the post and buckle together, maintaining the anchoring elementin a locked configuration. This configuration is shown in FIG. 5A. Inthis configuration, actuation element 206B (or “rod”) is reversiblycoupled to post 16. Rod 206B includes a portion that is disposed withina channel in post 16 such that bore 230 (see FIG. 5E) in the distalportion of rod 206B is aligned with bore 232 in post 16. Pin 234, whichis part of pin assembly 236 as can be seen in FIG. 4, extends throughboth rod bore 230 and post bore 232 to couple the rod to the post. Thedistal portion of pin assumes a curled or looped configuration, whichprevents rod 206B from disengaging from post 16. In FIG. 5A finger 206Ais reversibly coupled to buckle 18 via the interaction between tooth 239on buckle 18 and groove 238 on finger 206A (see FIG. 5E). In FIG. 5A,collar 22 is positioned over the engagement between tooth 239 and groove238 to retain the 206A and buckle 18 in a reversibly coupledconfiguration.

Once it has been determined to release the heart valve in place withinthe subject, pin 234 is first removed by retraction of pin assembly 236(see FIG. 4) in the proximal direction, which pulls the pin throughbores 230 and 232 and uncouples rod 206B from post 16, which is shown inFIG. 5B. Next, rod 206B is pulled back in the proximal direction viaactuation of an actuator on the delivery system handle. Once rod 206Bhas been pulled to the position in FIG. 5C, collar engagement 23 engagescollar 22 and pulls it in the proximal direction along with rod 206B.This causes the collar to be pulled proximally from the position in FIG.5C to the position in FIG. 5D. Retracting the collar to the position inFIG. 5D allows tooth 239 of the buckle to disengage groove 238 withcontinued retraction of rod 206B, which is shown in FIG. 5E. Both rod206B and finger 206A are uncoupled from the heart valve, and thedelivery system is now retracted from the patient with the medicaldevice implanted in place.

In some embodiments the axially directed force vectors applied by thefingers 206A to the buckles and the rods 206B to the posts can be insubstantially opposite directions to enhance the efficiency of theforeshortening and locking process. An advantage of coupling the fingersdirectly to the buckles is that the buckles are better aligned with theposts during the foreshortening and locking process. This can helpensure that the post, when pulled proximally, will better align with thebuckle such that the post can be efficiently locked with the buckle.When using an anchor that may become twisted or distorted under highforeshortening and locking forces (such as an anchor comprising abraided material), it can be beneficial to ensure that a buckle which iscoupled to the anchor (and thus may fall out of alignment with the post)remains properly aligned with the post. Directly coupling the fingers tothe buckle can provide these benefits. This can also increase thegeneral efficiency of proximally directed pulling forces because lessforce may be required to pull and lock the posts with the buckles. Whenincorporating actuators on a handle to control delivery and deploymentof a medical device, reducing the amount of force that is needed to beapplied to the handle actuator can simplify the delivery system design.

FIGS. 6A and 6B illustrate an alternative embodiment of post 250 whichis reversible coupled to actuation element 252. FIG. 6B is a partiallyexploded view identifying the components shown in FIG. 6A. Actuationelement 252 includes rod 254, tab deflector 256, and retaining clip 258.Rod 254 can be actuated in a proximal direction P by actuating anactuator on a handle disposed external to the patient as describedherein.

Rod 254 is attached to tab deflector 256 and to retaining clip 258. Rod254 includes, at its distal end, catch 260, which engages with clipelement 262 of retaining clip 258. Post 250 has an internal channeltherein adapted to slidingly receive retaining clip 258 and tabdeflector 256, each of which are adapted to receive rod 254 therein. Tabdeflector 256 includes rib element 264. Retaining clip 258 includes clipfeet 266. To lock the anchoring element (not shown), rod 254 is pulledin the proximal direction and clip feet 266 engage the distal end ofpost 250 and pull it in the proximal direction towards the buckle (notshown).

FIGS. 7A-7D show side-views of an exemplary locking sequence of post 250shown in FIGS. 6A and 6B to buckle 268 (anchor not shown). FIG. 7A showsrod 254 being actuated in the proximal directed by an actuation forcegenerated from an actuator on the handle of the delivery system externalto the patient. In FIG. 7A, post 250 is still distal to buckle 268. Asrod 254 continues to be pulled in the proximal direction, catch 260(shown in FIG. 6B) applies a proximally directed force to clip element262 (shown in FIG. 6B). This causes clip feet 266 to apply a proximallydirected force to the distal end of post 250. This causes the post tomove in the proximal direction. Post 250, tab deflector 256, andretaining clip 258 thus move towards buckle 268, as is shown in FIG. 7A.

Continued actuation of the actuator external to the patient causes thepost, the deflector, and the clip to be pulled further in the proximaldirection into a position within a channel within buckle 268, as isshown in FIG. 7B. Because rib element 264 of tab deflector 256 isdisposed adjacent groove 272 of post 250, rib element 264 preventsbuckle tooth 270 from engaging groove 272 of post 250 (shown in FIG.7B). This prevents the post from locking with the buckle until thephysician determines that it is appropriate to do so. Rib element 264thereby acts as a lock prevention mechanism. The post (and thus theanchor) can be moved distally to lengthen the anchoring element at thispoint by applying a distally directed force on post 250 using theactuator on the handle.

Once the desired position of the anchor has been obtained, rod 254continues to be actuated in the proximal direction. This can be doneusing the same actuator on the handle or a different actuator asdescribed in more detail below. The continued proximal force to rod 254causes feet 266 to be pinched inwards towards one another to therebydisengage and uncoupled them from the distal end of post 250. This pullsfeet 266 within the distal opening of post 250. This releases clip 258from post 250 and uncouples the rod, deflector, and clip from the post.Continued actuation of the actuator will move the cable, deflector andclip in the proximal direction to the position shown in FIG. 7C. Ribelement 264 is disposed proximal to tooth 270 and groove 272 and thus nolonger prevents them from locking together. The tooth therefore engagesthe groove, locking the post to the buckle (shown in FIG. 7C). Theanchor (not shown) is now locked in the fully deployed and lockedconfiguration. Continued actuation of rod 254 pulls the rod, clip, anddeflector from the patient, as is shown in FIG. 7D.

FIGS. 8A-8G illustrate a side view of a locking and release sequence ofan alternative embodiment of a post, buckle, and actuation elements. Thesystem includes actuation element 280 in the form of a rod, buckle 282,post 286, and clip 290. The clip 290 includes feet 294 and rib element292. Actuation of an actuator on the handle causes rod 280 to be pulledin the proximal “P” direction, as shown in FIG. 8A. Continued actuationpulls rod 280, post 286, and clip 290 through a channel within buckle282, as shown in FIG. 8B. As rod 280 continues to be pulled, a surfaceof buckle tooth 284 slides over surface 295 of clip 290, as shown inFIG. 8B. Feet 294 engage the distal end of buckle 282, as shown in FIG.8C. The top view of this position is shown in FIG. 8G. Between thepositions shown in FIGS. 8B and 8C, rib element 292 has prevented thepost from locking with the buckle. In the position shown in FIG. 8C,tooth 284 is engaging surface 287 of post 286. The location of feet 294ensures post groove 288 has been pulled far enough proximally before theclip 290 is removed from the post. From the position shown in FIG. 8C,continued proximal movement of rod 280 will cause feet 294 to pinchtogether and retract into the channel in buckle 282. This releases clip290 from post 286 and pulls the rod and clip in the proximal direction.Once the clip is released from the post, the post will begin tonaturally move in the distal direction because the anchoring element(not shown, but in this embodiment comprises a braided material) beginsto revert naturally to a self-expanded, partially deployed memoryconfiguration (which is more fully described in the applicationsincorporated by reference herein). As the post begins to move distally,tooth 284 engages post groove 288 as is shown in FIG. 8E. This locks thepost and buckle and locks the anchoring element in a fully deployed andlocked configuration. The rod and clip can now be removed from thepatient, as is shown in FIG. 8F.

FIGS. 9 and 10 show two alternative embodiments incorporating featuresof the lock and release embodiments above. The embodiment in FIG. 9 issimilar to that shown in FIGS. 5A-5E, although rod 304 includes feet 306which are similar to the feet shown in the embodiments in FIGS. 6A-8G.In this embodiment pin 234 from FIGS. 5A-5E is not needed, as therelease of rod 304 from post 300 occurs when rod 304 is pulledproximally, causing feet 306 to pinch inwards and disengage from thepost.

FIG. 10 shows an alternative embodiment which incorporates compressiblefeet 316 at the distal end of rod 314 and release pin 318 (actuated inthe same way as shown in the embodiment in FIGS. 5A-5E). The embodimentin FIG. 10 can be thought of as a hybrid design between that shown inFIGS. 5A-5E and 9. One difference between the embodiment in FIGS. 5A-5Eand 10 is that in FIGS. 5A-5E there is a slot 230 in the rod that pinsthe rod to the post. When pin 234 is under tension in FIGS. 5A-5E, thepin is in shear, which increases the likelihood of damaging the pin. Inthe design in FIG. 10, the slot 230 is not present, but rather the twofeet 306 simply extend distally from a distal portion of the rod. Pin318 maintains feet 316 in the spread-apart position shown in FIG. 10,essentially holding them open and maintaining the coupling between thefeet and the post. In this design, the pin is in compression between thefeet, rather than being in shear. Once the pin removed, a lower releaseforce can then be applied to the rod to cause the feet to uncouple fromthe post. Having the pin in compression rather than shear is less likelyto cause damage to the pin.

Each of FIGS. 11A-11D shows a side view and perspective view,respectively, of an alternative embodiment including post 320 andactuation element 322 in a sequence wherein post 320 changesconfiguration from a position in which it is not locked to acorresponding buckle 321 to a locked position, and in which theactuation element 322 is released from the post. Buckle 321 is not shownin the sequence for clarity, although buckle 321 is shown in FIG. 11A todisplay the relative positions of the post, actuation element, andbuckle. FIGS. 12A-12C show the locking and release sequence includingbuckle 321.

In FIG. 11A actuation element 322 is reversibly coupled to post 320.Actuation element 322 includes rod 324, post lock prevention element326, and post lock actuator 328. Post 320 includes post lock element330. FIG. 11A illustrates an initial configuration of the respectivecomponents before the post is pulled towards the buckle. To activelyforeshorten the anchoring element (not shown), the rod 324 is retractedin the proximal direction. Post lock prevention element 326 is initiallyengaged with post lock element 330, and thus proximal retraction of rod324 causes proximal movement of post 320. Rod 324 continues to be pulledproximally until post 320 is pulled within buckle, as can be seen inFIG. 12A. In FIG. 12A the post is not yet locked to the buckle, and postlock element 330 is proximal to buckle lock element 332. To lock post320 to buckle 321, a separate actuator (not shown) is actuated toretract the post lock prevention element 326 in the proximal directionto disengage post-lock prevention element 326 from post lock element330, as shown in FIGS. 11B and 12B. Alternatively, rod 324 and post lockprevention element 326 may be engaged in a manner such that a continuedproximal force applied to rod 324 will disengage post lock preventionelement 326 from post lock element 330. Because the anchoring elementhas a memory configuration that is longer than the fully expanded anddeployed configuration, once post-lock prevention element 326 isdisengaged from post lock element 330, the anchor will attempt to returnto its elongated memory configuration. Thus, post 320 begins to move inthe distal direction. Distal movement of post 320 causes post-lockactuator 328 to apply a radially outward force to post lock element 330,moving it to a locked configuration shown in FIGS. 11C and 12C.Alternatively, or in addition to, once lock prevention element 326 isdisengaged from post lock element 330, continued proximal retraction ofrod 324 causes post-lock actuator 328 to apply a radially outward forceon post lock element 330. Continued distal movement of post 320 causespost lock element 330 to engage with buckle lock element 332, lockingpost 320 to buckle 321. The lock prevents further distal movement of thepost relative to the buckle, locking the anchor in an axially compressedand fully deployed configuration. Actuation element 322 can now bewithdrawn proximally and removed from the patient.

FIG. 13 shows an alternative embodiment of post 340 and clip 342, whichincludes deformable element 344. FIGS. 14A-14E show a sequence oflocking post 340 to buckle 348 and releasing clip 342 from post 340. Arod (not shown) is attached to clip 342, similar to the embodimentsdescribed above. In the position shown in FIG. 14A, the proximal end ofdeformable element 344 engages surface element 346 of post 340. Thisengagement maintains the clip within the post as the clip is pulledproximally. This engagement also pulls the post proximally as the clipis pulled proximally. As the actuator is actuated the cable pulls thepost and clip within the buckle 348 as shown in FIG. 14B. Continuedactuation from the position shown in FIG. 14C causes tooth 350 of buckle348 to engage and deform deformable element 344. Deforming element 344allows tooth 350 to engage groove 352 to lock the buckle and post. Thisstep also releases deformable element 344 from engagement with surface346, thus releasing the clip from the post, as is shown in FIG. 14D.This step therefore also releases the rod and clip from the post. FIG.14E shows the clip completely withdrawn proximally from the post.

FIGS. 15A, 15B, 16A, and 16B illustrate an alternative embodiment of thepost lock and release mechanism. The embodiment in FIGS. 15A-16B workssimilarly to those described above in that an actuator is actuated topull the actuation element, or rod, which pulls the post towards thebuckle to lock the anchoring elements. Rod 354 includes a clip similarto the clip in the embodiment in FIGS. 6A and 6B. FIG. 15A is aperspective view and FIG. 15B is a side view after rod 354 has beenactuated and pulled proximally such that tooth 358 of buckle 352 islocked with groove 362 of post 360. Prior to the position shown in FIGS.15A and 15B, surface 356 of rod 354 prevented tooth 358 from lockingwith the groove in the post. The clip at the distal end of the rod isengaged with a deformable element of the post such that continuedactuation of the rod causes the deformable element to deform and releasethe post from the rod. This rod can then be removed from the patient bycontinued actuation of the actuator. Alternatively, a pin similar to pin234 in FIGS. 5A-5E can be incorporated into the embodiment, such thatthe pin is removed when it is desirable to release the rod from thepost, as is described above.

FIGS. 16A and 16B illustrate an unlocking of the post and buckle whichare locked in FIGS. 15A and 15B. This unlocking step must be performedbefore the heart valve is released from the delivery system. Rod 354 ispushed distally, causing surface 364 (unlocking element) of the rod toengage and disengage tooth 358 from the groove in the post. Continueddistal movement of the rod pushes the post in a distal direction, whichlengthens the anchoring element.

In some embodiments, the fingers can be made of an alloy that is heatset to a memory expanded configuration. The rods can comprise, forexample, stainless steel. The outer tube can be made of, for example, aheat-shrink polymer, but can be any suitable material. The outer tubeprovides enhanced column strength to the fingers, which can beadvantageous when under the forces applied during the activeforeshortening of the anchoring element.

In the embodiments above reference was made to a delivery system handledisposed external to the subject, which is used to control the actuationof the actuation elements and the sheath. The deployment of the medicalimplant as described herein can be controlled by actuators (e.g., knobs,levers, etc) on the handle, which are actuated by the physician tocontrol the deployment of the device. It may be desirable to be able toperform multiple deployment steps with as few actuators as possible tosimplify the delivery and expansion process. It may further be desirableto perform certain deployment steps with a single actuator, perhaps evenactuating a single actuator with a singular type of movement (e.g.,rotating a knob in a single direction) to perform multiple parts of thedeployment process. This can make the procedure easier for the physicianbecause a hand used to actuate the handle actuator does not need to beremoved from the actuator to perform multiple steps. In some embodimentsof the delivery system described below, the actuation steps ofunsheathing the anchoring element and locking the posts with buckles areperformed with a single actuator on a handle of the delivery system.Having a single actuator on the handle which can perform multipledeployment steps can simply the overall procedure. Using a singleactuator to control multiple deployment steps can also insure that thesteps are performed in a specified sequence, and making sure that asecond step does not occur before the occurrence of a first step.

In embodiments described herein in which actuation of a single actuatorin a singular type of motion moves a plurality of delivery systemcomponents, the singular type of motion can be performed to move morethan one delivery system component without any other interveningactuation step being performed. In some embodiments, the user can stopthe actuation of the actuator in the singular type of motion, and thencontinued the actuation. A singular type of motion includes embodimentsin which a period of time passes without any actuation. That is, theuser may start to actuate the actuator, wait a period of time (forexample, to determine if the position of the medical device issufficient based on an imaging technique), then continue to actuate theactuator. This falls under the “singular” type of motion as describedhere.

A potential challenge in using a single actuator to actuate multiplecomponents of a delivery system arises when the actuatable componentsare to be actuated independently of one another, or when they are to beactuated independently of one another during portions of the procedurebut actuated at the same time during other portions of the procedure, orwhen they must be actuated at the same time but at different rates ofmovement. Provided below are delivery systems in which actuation of asingle actuator actuates a plurality of delivery system componentswherein a first of the plurality of components and a second of theplurality of components are each actuated independent of the other. Insome embodiments the first and second components are also adapted to beactuated at the same time as one another, and in some embodiments atdifferent rates while they are both being actuated.

In some embodiments of the delivery system, a single actuator is used toboth proximally retract the sheath during the unsheathing process (forexample, as shown in the exemplary method in FIGS. 3B-3F) and toproximally retract the actuation elements which are coupled to theposts. That is, a single actuator is actuated in a single manner to bothunsheath the implant as well as to lock the implant in a fully deployedand locked configuration. Incorporating a single actuator into thedelivery system which can be actuated in one direction or manner to bothdeploy the implant from the sheath as well as reconfigure it to itsfinal deployed configuration can greatly simplify the deploymentprocedure for the physician.

During a first portion of the deployment of the implant only the sheathis pulled in the proximal direction, which unsheathes the implant.During a second portion of the deployment only the posts are pulledproximally, which moves the posts towards the buckles to lock theanchoring element in the locked configuration. During a third portion ofthe procedure both the sheath and the actuation elements reversiblycoupled to posts are pulled in the proximal direction, which may resultin variable rates of movement of the sheath and the actuation elements.The single actuator must therefore account for both the dependent andindependent motions of a plurality of delivery system components.

FIGS. 17A-17D illustrate an exemplary delivery system in which a singleactuator on a handle selectively actuates a plurality of delivery systemcomponents. While this delivery system design can be used to selectivelyactuate a plurality of delivery system components in almost type ofmedical device delivery system, it will be described in relation todeployment of a replacement heart valve. In addition, while the singleactuator can be adapted to actuate different types of components thanthose which are described herein, it will be described as controllingthe movement of a sheath and an actuation element which actuates aportion of a replacement heart valve.

FIGS. 17A-17D show components of delivery system 370 which are housedinside a handle housing (not shown), including outer tube 380, rotaryactuator 372 (which is adapted to be actuated by a user), lead screw374, rod carriage 376, rod carriage screw 378, sheath carriage 384,sheath carriage screw 386. Proximal movement of rod carriage 376 movesthe rods in the proximal direction, which causes a proximally directedforce to be applied to the posts described herein (and distal movementof post puller carriage 206 causes a distally directed force to beapplied to the posts). Proximal movement of sheath carriage 384 causesthe sheath to be retracted proximally to unsheathe the implant (anddistal movement of sheath carriage 384 causes the sheath to be moveddistally to re-sheath the implant). In one embodiment, the sheath has anadapter bonded to its proximal end which is screwed to the sheathcarriage. Movement of the sheath carriage, through rotation of the leadscrew, therefore directly moves the sheath. In one embodiment the rodsare bonded inside a hypotube and the hypotube is pinned to a forcelimiting member, which is directly attached to the rod carriage.Movement of the rod carriage therefore moves the rods. Rotation ofrotary actuator 372 translates rotational movement into linear movementof rod carriage screw 378 and sheath carriage screw 386.

Tube 380 includes an internal female thread including a linear femalethread 383 along two portions of tube 380 and a partiallyhelically-shaped female thread 382 along a portion of the tube disposedbetween the linear female thread portions 383. Both the rod carriagescrew 378 and sheath carriage screw 386 include an internal male threadwhich engages the female threads of screw 374 and allows rotation ofactuator 372 to translate to movement of the rod carriage screw 378 andsheath carriage screw 386. The sheath carriage screw 386 includes malenub(s) 385 which engage linear female thread 383 in the configurationshown in FIG. 17A. The sheath carriage screw 386 also has an outer malethread 387 (see FIG. 17D) which engages with an internal female threadin sheath carriage 384. FIG. 17A shows the delivery system in aconfiguration in which the implant is sheathed within the sheath and theposts are not locked to the buckles. Initial rotation of actuator 372causes sheath carriage screw 386 to move linearly in the proximaldirection. Because of the interaction between the male thread 387 andthe female thread within sheath carriage 384, proximal movement ofsheath carriage screw 386 causes proximal movement of the sheathcarriage 384, as is shown in the transition from FIG. 17A to 17B. Thismovement causes proximal movement of sheath, such as is required tobegin unsheathing the implant to allow it to self-expand.

This initial rotation of the actuator 372 does not, however, translateinto proximal motion of rod carriage 376. This initial rotation ofactuator 372 causes rod carriage screw 378 to move proximally, butbecause rod carriage screw 378 has a male nub (not shown) similar to themale nub 385 on the sheath carriage screw, the rod carriage screwrotates within outer tube 380. The rod carriage 376 has an internalfemale thread which mates with male thread 379 on the rod carriage screw378. These threads allow the rod carriage screw 378 to rotate within rodcarriage 376 without causing the rod carriage to move proximally. Thisinitial rotation of actuator 372 thereby results in lost motion of therod carriage 376, as is shown in the transition from FIG. 17A to 17B. Asthe sheath begins to be pulled back, the rods therefore do not pull onthe posts.

In the configuration in FIG. 17B, both males nubs of the carriage screwsare aligned with the respective linear female threads 383. Continuedrotation of actuator 372 therefore results in proximal movement of bothof the carriage screws 386 and 378. Because of the threaded interactionbetween the carriages and their respective screws, both carriages movein the proximal direction This is illustrated in the transition fromFIG. 17B to 17C. During this portion of the procedure, both the sheathand the rods are being pulled in the proximal direction.

In the configuration in FIG. 17C, the bottom male nub 385 (not shown)engages helical thread 382. Continued rotation of actuator 372 thereforeresults in rotation of sheath carriage screw 386 relative to outer tube380. This causes sheath carriage screw 386 to unscrew from sheathcarriage 384, as is shown in the transition from FIG. 17C to FIG. 17D.This results in the sheath carriage not moving in the proximal direction(i.e., lost motion). The threaded interaction between rod carriage 376and rod carriage screw 378, however, translates into proximal movementof the rod carriage 376, as is shown in the transition from FIG. 17C to17D. During this portion of the procedure, the rods are being pulledproximally but the sheath is not being actuated.

The movements of the carriages can also be reversed by rotating theactuator in the opposite direction.

It should be noted that the female threads on lead screw 374 can have adifferent pitch along the length of the screw, as is shown in FIGS.17A-17D (although the pitch of the thread on lead screw 374 may also beconstant along the length of lead screw 374). As shown, the pitch isgreater on the portion where the sheath carriage screw interacts withthe lead screw 374 than the pitch where the rod carriage screw interactswith the lead screw 374. This results in the sheath carriage moving agreater distance that the rod carriage during the transition from FIG.17B to 17C. Thus, FIGS. 17A-17D illustrate not only lost motion but adifferent rate of motion of two moving delivery system components basedon actuation of a single actuator (e.g., the rotary actuator 202).

FIGS. 18A-18D illustrates a sequence of movements of male threadedelement 412 over female threaded element 400 which has a varying pitchand a varying diameter. The lead screw 374 from FIGS. 17A-17D can havethe varying pitch and diameter of female element 400, and the carriagescrews in FIGS. 17A-17D can incorporate the features of male element412. Section 402 has a smaller pitch than sections 404 and 406, whilethe diameter of section 406 is greater than the diameter in sections 402and 404. The lead portion of male thread 410 has a greater height (seeFIG. 18D), which allows it to engage female thread 406, 404, as well as402. The male threads 408 have a smaller height than the lead portion.The male threads 408 are large enough to engage female threads 406, butnot 404 or 402. This design allows for varying degrees of movement ofmale element 412 over the length of female threaded element 400. Themale element 412 moves a greater distance when threaded in section 406than in section 402, due to the difference in pitch. This can allow adelivery system component to move at first rate, followed by movement ata second rate (in this case, the second rate of movement is less thanthe first). This variable pitch design can be incorporated into any ofthe delivery systems described herein.

FIG. 19 illustrates a barrel cam design which functions with a variablepitch in a similar manner to the design shown in FIGS. 18A-18D. Onedifference between the two embodiments is that threads 433 and 435 inthe embodiment in FIG. 19 are integrated into barrel housing 421 insteadof a central lead screw. As shown in FIG. 19, sheathing carriage 425rotates on first thread 433 and rod carriage 423 rotates on secondthread 435 in barrel housing 421. Lost motion is accounted for bybringing the pitch angle to, or near to, 0 so the carriage rotates butdoes not translate (or translates a minimal amount) within barrelhousing 421. Each of the carriages also includes nubs 429 for trackingin threads 433 and 435. The carriages also include holes 427 for guidetubes 431.

FIGS. 20A-20C illustrate an alternative design to account for lostmotion including handle housing 452, a pair of gears 454, rotaryactuator 456, rod lead screw 458, rod carriage 460, rod carriage spring462, rod carriage screw 464, sheathing lead screw 466, sheath carriage468, sheath carriage screw 470, sheath carriage spring 472. Rotaryactuator 456 turns both gears 454, one geared to the rod lead screw 458and one geared to the sheathing lead screw 466. Different pitches oneach lead screw would allow for different linear motion rates for therod screw 464 and sheathing screw 470. In an initial configuration shownin FIG. 20A, spring 462 is fully compressed and spring 472 is unloaded.Rotation of actuator 456 turns both lead screws 458 and 466, causingboth the rod screw 464 and sheathing screw 470 to move proximally. Theresistance to compression of spring 472 between the sheathing carriage68 and sheathing lead screw 466 causes the sheathing carriage 468 tofollow the proximal movement of sheathing screw 470, as is shown in thetransition between FIGS. 20A and 20B. The force unloading of spring 462causes the rod carriage 460 to remain stationary while rod screw 464moves proximally, as is shown in the transition from FIG. 20A to FIG.20B.

When the rod screw 464 reaches the proximal end of the rod carriage 460,continued rotation of actuator 456 causes both carriages to move, as isshown in FIG. 20B (both carriages in motion). Upon continued actuationof actuator 456, a stop (not shown in FIG. 20C) causes the sheathingcarriage 468 to stop moving proximally. Continued rotation of theactuator 456 causes the continued movement of the sheath carriage screw470 (but not sheath carriage 468) and the compression of spring 472.This allows for the locking of the anchor through proximal movement ofthe rod carriage 460 without motion of the sheath.

Actuating the actuator 456 in the reverse direction unlocks the anchorthrough distal motion of the rod carriage 460. Compression of spring 472limits motion of the sheathing carriage 468 until the sheathing screw470 is fully seated in the sheathing carriage 468. The two carriagesthen move together distally until the rod carriage 460 reaches a stop(not shown) causing the rod screw 464 to move distally while the rodcarriage 460 does not move and spring 462 is compressed.

FIGS. 21-22 illustrate exemplary designs for decoupling the motion ofthe rods and outer sheath. In FIG. 21, a single actuator is geared to agear with a cam on the proximal surface. The cam causes theengagement/disengagement of a clutch that is attached to a lead screw.When the clutch is engaged, the lead screw turns which causes a carriage(not shown) to move proximally or distally depending on the direction ofmovement of the actuator. When the clutch is not engaged, the lead screwdoes not turn and the carriage is stationary.

In FIG. 21 nut 502 (either for the rod or sheath) is connected to thecarriage 504 (either for the rod or sheath) via a male tab 506 thatengages with a female feature 508 in the carriage 504. The engagementbetween the nut 502 and the carriage 504 via the tab 506 causes thecarriage 504 to move with the nut 502 as the lead screw 510 is turned(by an actuator not shown). The nut 502 has a nub 512 which travelsalong a path 514 in the housing. A jog 516 in the path 514 causes thenut 502 to rotate counterclockwise relative to the carriage 504. Thismotion causes the tab 506 to disengage from the female feature 508,releasing the nut 502 from the carriage 504. Since the nut 502 andcarriage 504 are no longer joined, continued actuation (e.g., rotation)of the actuator moves only the nut 502. Rotating the actuator in theopposite direction causes the nut 502 to move back into contact with thecarriage, reseating the nut tab 506 in the carriage and the carriage 504then moves with the nut 502.

FIG. 22 shows a portion of delivery system 600 including lead screw 602with region 606 with female thread and region 610 without threads.Sheath carriage 604 includes male threads 614 which engage with femalethreads 606 on lead screw 602. Sheath carriage 604 also includes lockelement 608 which is adapted to engage with lock lip 612 on lead screw602 to lock the carriage 604 onto lead screw and prevent the carriage604 from moving in the distal direction D. Rotation of an actuator onthe handle (not shown) causes lead screw 602 to rotate, which causes thecarriage 604 to move proximally. This retracts the sheath in theproximal direction without moving the posts. Continued proximal movementcauses lock element 608 to engage and lock with lock lip 612. Becausethe lead screw does not have any threads in region 610, continuedrotation of lead screw 602 does not result in movement of the carriage604.

FIGS. 23A and 23B illustrate a proximal portion of an exemplary handlewhich is used in the deployment of the heart valve shown in FIGS. 4 and5A-5B. The handle includes housing 620, first actuator 624 in the formof a rotary actuator, slidable door 622, and second actuator 626 whichcan only be accessed when the door 622 has been slid forward from thefirst position in FIG. 25A to the second position in 25B. In thisembodiment, rotary actuator 624 controls the movement of the sheath(such as is shown in FIGS. 3B-3F) and the movement of actuation elements206B shown in FIGS. 4 and 5A-5B. In one embodiment, actuator 624controls the movement of sheath and the actuation elements as shown inFIGS. 17A-17C, such that actuation of actuator 624 independently anddependently moves the sheath and actuation elements. Once the anchoringelement is locked by the locking of posts to buckles, the physicianslides door 622 to the position shown in FIG. 23B and actuates secondactuator 626. Actuation of actuator 626 retracts pin assembly 236 inFIG. 4, which causes the three pins 234 to be removed from the boresthrough the posts and actuation elements, uncoupling the posts from theactuation elements 206B.

In one embodiment, continued actuation of actuator 626 also furtherretracts the actuation elements 206B from the position shown in FIG. 5Bto the position shown in 5E. FIG. 23C illustrates an enlarged portion ofhandle 630 of an exemplary delivery system with a design which allowscontinued actuation of actuator 626 to further retract actuationelements 206B (second actuator 626 from FIGS. 23A and 23B not shown).The locking and sheathing drive ring actuates the locking and sheathingcarriages via the lead screw similarly to the method described inreference to FIGS. 17A-17D. Handle 630 includes locking and sheathingdrive ring 631, locking and sheathing lead screw 632, locking carriage633, release pin carriage 635, lost motion barrel 629, release pinmandrels 636 (shown within hypotube), rod actuation mandrels 634 (shownwithin a hypotube), and force limiter 638. Force limiter 638 includestrack 637 in which release pin carriage 635 moves when pulledproximally. The release collar actuates a separate smaller lead screw639 (normally driven by locking carriage 633) which pulls proximallyrelease pin carriage 635. When the physician is ready to remove thepins, the second actuator on the handle (not shown) is actuated, whichengages the release lead screw 639, causing it to rotate. This pullsrelease collar 636 proximally in track 637, which causes release pinmandrels 636 to be pulled back proximally, releasing the pins from theposts and uncoupling the rods from the posts. Continued actuation of thesecond actuator continues to pull the release carriage until it reachesthe proximal end of force limiter 638. When carriage 635 bottoms out onthe proximal end of force limiter 638, it moves the portion of the forcelimiter in which it sits proximally relative to the other portion of theforce limiter. This causes rod mandrels 634 to be pulled proximally,which pulls the rods in the proximal direction. Thus, the secondactuator can be used to release the pins as well as continue to pull therods back in the proximal direction.

Alternatively, the handle can be designed such that rotary actuator 624can be further actuated to proximally retract actuation elements 206Bafter the pin has been removed. The delivery system can be then removedfrom the patient.

The medical implants described herein can be recollapsed and resheathedat least partially back inside the sheath after the entire implant hasinitially been deployed from the sheath. This is because at least aportion of the implant remains reversibly coupled to a portion of thedelivery system after the implant is deployed from the sheath (e.g., seeFIG. 3F). Even after the anchoring element is locked in the fullydeployed configuration, the post can be unlocked from the buckle in someembodiments and thereafter the anchoring element can be resheathed intothe sheath. Being able to resheath an implant after it has been deployedfrom a delivery sheath or catheter is advantageous because it allows forthe implant to be removed from the patient or repositioned inside thepatient if needed. For example, the functionality and/or positioning ofa replacement heart valve can be assessed once the replacement heartvalve is in the configuration shown in FIG. 3F (and continually assessedas the anchor begins to be locked in the expanded and lockedconfiguration), and can then be resheathed and subsequently repositionedor removed from the patient if needed.

While the resheathing processes and delivery systems to perform theresheathing described herein make references to replacement heartvalves, a wide variety of medical devices may benefit from theresheathing aids described herein. For example, an expandable stentwhich remains reversibly coupled to the delivery system after the stenthas been deployed from a delivery catheter or sheath may benefit fromhaving any of the resheathing aids described herein incorporated intothe delivery systems thereof

To resheath the heart valve, the sheath is advanced distally relative tothe catheter. Alternatively, the catheter can be withdrawn proximallyrelative to the sheath. Distal movement of the sheath relative to thecatheter causes the fingers, which are coupled to the distal end of thecatheter, to collapse radially inward. This causes the proximal end ofthe anchor to collapse. Continued distal movement of the sheath causesthe rest of the heart valve to elongate and collapse, allowing thesheath to recapture the anchoring element.

In embodiments in which the anchoring element comprises a braidedmaterial, distal advancement of the sheath may result in portions of theproximal end of the anchor to get caught, or stuck, on the distal end ofthe sheath. This can prevent resheathing or it can reduce theresheathing efficiency.

FIG. 24 illustrates an alternative delivery system 640 including sheath644, delivery catheter 646, and sheathing assist element 642. Sheathingassist element 642 is a braided structure, and can be similar to thebraided anchoring elements described herein. The sheathing assistelement 642 generally has a memory configuration in which the distal endof the sheathing assist element 642 has a diameter larger than thediameter of the proximal end of the anchoring element 649. The deliverysystem includes fingers 647 (only two can be seen) reversibly coupled toa proximal region of replacement heart valve 648 (replacement leafletsnot shown for clarity). The proximal end of sheathing assist element 642is coupled to the distal end of delivery catheter 646. Fingers 647 arealso coupled to the distal end of catheter 646, and are generally“within” or radially inward relative to sheathing assist element 642.FIG. 24 shows a replacement heart valve after the sheath has beenwithdrawn, allowing the anchoring element to expand to a memoryconfiguration, and has not yet been actively foreshortened.

To resheath the implant, the sheath is advanced distally relative to thecatheter and implant. This can be done by actuating an actuator of ahandle, as described above. Because the proximal end of the sheathingassist element is fixed to the distal end of the delivery catheter, thedistal end of the sheath can easily pass over the proximal end of thesheathing assist element without getting caught. Continued distalmovement of the sheath causes at least the distal portion of thesheathing assist element to elongate and partially collapse in diameter.As the sheathing assist element elongates, the distal end of thesheathing assist element moves distal relative to the proximal end ofthe anchor. Continued distal movement of the sheath continues tocollapse the distal end of the sheathing assist element and at least adistal region of the sheathing assist element will engage at least theproximal end of the anchor. The sheathing assist element will thereforeprovide a surface over which the sheath can pass without the risk ofgetting caught on the proximal end of the anchor. The sheathing assistelement may additionally apply a radially inward force to the proximalend of the anchor, assisting in the collapse of the proximal end of theanchor. As the sheath continues to be advanced distally, the anchor iscollapsed and is resheathed back within the sheath. In some embodimentsthe sheathing assist element is a polymer mesh.

In some embodiments the sheathing assist element can also act as anembolic filter. Once unsheathed, the sheathing assist element can trapemboli traveling downstream to the target location, yet allowing bloodto pass through the assist element. In such embodiments, the distal endof the sheathing assist element can be configured and arranged to have amemory diameter that is as close as possible to the diameter of thelumen in which it is to be disposed. Exemplary materials for embolicfilters are known in the art.

FIGS. 25-28 illustrate alternative delivery systems with alternativesheathing assist element 660. Sheathing assist element 660 includesthree (3) collapsible blades 662. The blades are fixed to one another attheir proximal ends at hub 664 (see FIG. 28). Hub 664 is axially movablerelative to fingers 666 and catheter 668, but the distal region ofcatheter 668 includes a hub stop 670 which is adapted to engage with thehub and prevent movement of the hub proximally relative to the hub stop.As sheath (not shown) is advanced distally over catheter 668, it beginsto collapse fingers 666. As the fingers collapse radially inward, thehub can then move distally over the fingers. As the fingers collapse,the proximal end of the anchor begins to collapse and the hub continuesto be advanced distally. Eventually the distal ends of blades 662 coverthe proximal end of the anchor, and the sheath can then be advanced overthe anchor without getting caught on the proximal end of the anchor. Insome embodiments the blades are adapted to collapse inwards onthemselves as the sheath applies a force to them.

In the embodiment shown in FIG. 26, sheathing assist element 660includes optional finger openings 672 which are adapted to allow thefingers to be passed therethrough. Openings 672 can be designed to haveany shape (e.g., rectangular, circular, etc) to allow the hub to beeasily moved distally relative to the fingers. In the embodiment in FIG.28, the blades have optional slits 674 to assist in their collapse.

FIG. 29 shows an embodiment of sheathing assist element 680 whichinclude arms 682 and teeth 684 at their distal ends. The teeth areadapted to engage the crowns of the braid, which are formed where abrand strand turns at an end of the braid (or other proximal region of anon-braided anchor) and allow the sheath to be advanced distally overthe anchor. Each arm 682 can have any number of teeth 684. The arms canbe adapted to respond to an applied force from the sheath such that theychange to a second configuration with a bend such that a distal portionof the arms are bent radially inward to engage the proximal end of theanchor.

FIG. 30 shows an alternative embodiment of a sheathing assist element670 which is comprised of stent element 672. Sheathing assist element670 functions similar to the embodiment shown in FIG. 26, but is notcomprised of a braided material. The stent can be made from, forexample, an alloy or any other suitable material as is known in the artof stents.

FIG. 31 shows an alternative embodiment of sheathing assist element 680which includes curled elements 682 (anchor not shown). The proximal endof the curled elements 682 can be coupled to a hub as described above inother embodiments, or each of the curled elements can be individuallyaffixed to the catheter. As the sheath is advanced distally, the forceof the sheath causes the distal ends of the curled elements to uncurland straighten. The distal ends of the straightened element extend overand distal to the proximal end of the anchor, and allow the sheath to beadvanced over the proximal end of the anchor without getting caught onthe crowns of the anchor. The curled elements can be made of, forexample, stainless steel or any other suitable material.

In an alternative embodiment shown in FIGS. 32 and 33, sheathing assistelement 684 comprises a plurality of arms 686 (twelve arms are shown inFIGS. 32 and 33), each which have a distal end with male locking element688. Each arm 686 includes female locking element 690 disposed closer tohub 692 than the male locking element 688. In FIGS. 32 and 33, the malelocking elements have an arrowhead shape and the female lock elementsare slot-shaped. Hub 692 includes an opening 694 therein to allowcontrol wire 696 to pass therethrough. Control wire 696 has an enlargedelement at its distal end (not shown) which prevents the enlargedelement from being pulled proximally through opening 694. In thedelivery configuration, each arm 686 extends distally from hub 692 andthe distal region of each arm distal to the slot is wrapped around acrown of the anchor (see FIG. 33). The male lock elements 688 areengaged with female lock elements 690. When the replacement heart valveis to be resheathed, a proximally directed force is applied to thecontrol wire 696, which prevents the crowns from extending radiallyoutward, thus allowing the sheath to be advanced distally over thecrowns of the proximal end without getting stuck. Alternatively, aproximal force is not required, and the engagement of arms 686 and thecrowns of the anchor prevent the crowns from getting stuck on thesheath. A proximally directed force on the hub will release thearrowheads from the slots, releasing the arms from the anchors. Thisreleases the implant from the arms.

In alternative embodiments shown in FIGS. 34-37, the delivery systemsinclude wires or sutures 700 which are coupled at their proximal ends toa delivery system component (e.g., the distal end of catheter 702, anactuator in a handle, etc.), and are each wrapped around a crown of theanchor. The distal ends of wires or sutures 700 have an enlarged element704 such as a spherical element which is adapted to engage with annulardetent 706 in the outer surface of catheter 702. Sheath 708 maintainsthe engagement of the enlarged element 704 and detent 706. The distalend of the wire or suture 700 can simply comprise one locking elementwhile the catheter outer surface can include a second locking element.The sutures 700 provide a radially inward force to the crowns, helpingthe sheath extend over them during resheathing. Once the outer sheath ispulled proximally relative to the catheter, the enlarged element isreleased from the indent, and the wire/suture 700 can be released fromthe crowns of the anchor. In the alternative exemplary embodiment shownin FIG. 35 the catheter includes multiple detents 706.

FIGS. 38-41 illustrate an alternative embodiment of sheathing assist710, which includes a plurality of arms attached to the distal end ofcatheter 714. The arms include two types of arms 718 and 720, whereinarms 718 are slightly longer than arms 720. The arms are formed from awire segment with a bend at their distal ends, wherein the two ends ofthe arms are coupled together at the proximal end 726 of the sheathingassist 710. Arms 718 extend from the catheter to the anchor and thedistal ends are weaved into the braid of the anchor. That is, the distalends of arms 718 are disposed radially within the braided anchor, as canbe seen in FIGS. 39-41. Arms 718 are attached to stiffening elements722, which are shorter than both arms 718 and arms 720. Stiffeningelement 722 is attached to arm 718 at attachment point 724, which canbe, for example, a weld. As can be seen, stiffening elements 722 aredisposed within the wire segments of arms 718, which increases thestrength of arms 718. Sheathing assist also includes arms 720 which areshown shorter than arms 718, although they could both be substantiallythe same length. As can be seen in FIG. 38, two arms 720 are attachedtogether at attachment points 724. Arms 720 are positioned radiallyoutwards of braid, unlike arms 720 which are weaved into the braid anddisposed radially inside the braid. Arms 720 help apply a radiallyinward force on the braid as the sheath is advanced distally. Arms 718also help apply a radially inward force on the braid as well, and thetwo sets of arms ensure that the distal end of the sheath doesn't getcaught on the anchor.

In an alternative embodiment, the proximal crowns of the braided anchorare heat-set in a configuration in which the crowns are bent radiallyinward (relative to longitudinal axis of the braid and relative to therest of the anchor), to assist the sheath in the resheathing process.The crowns are bent inward to prevent the sheath from getting caught onthe crowns.

Although the present disclosure has been described in connection withthe exemplary embodiments described above, those of ordinary skill inthe art will understand that many modifications can be made thereto.Accordingly, it is not intended that the scope of the present disclosurein any way be limited by the above exemplary embodiments.

What is claimed is:
 1. A medical device system, comprising: a deliverysystem including an outer sheath and an inner member slidably receivedwithin the outer sheath; and a replacement heart valve implant includingan expandable anchoring element, the expandable anchoring element beingreleasably coupled to the distal end of the inner member, wherein thereplacement heart valve implant includes a plurality of valve leafletsdisposed within the expandable anchoring element; wherein the expandableanchoring element includes a plurality of openings configured toreleasably engage a portion of the inner member, wherein the portion ofthe inner member configured to be releasably engaged by the expandableanchoring element includes a plurality of flexible members, eachflexible member corresponding to one of the plurality of openings andwherein the inner member includes a plurality of detents proximate adistal end of the inner member, each flexible member being configured toengage one of the plurality of detents to releasably couple theexpandable anchoring element to the distal end of the inner member. 2.The medical device system of claim 1, wherein the expandable anchoringelement is configured to shift between a collapsed deliveryconfiguration and an expanded deployed configuration.
 3. The medicaldevice system of claim 1, wherein the delivery system includes a handledisposed at a proximal end of the outer sheath.
 4. The medical devicesystem of claim 1, wherein the expandable anchoring element isreleasably coupled to the distal end of the inner member at multiplediscrete locations.
 5. The medical device system of claim 1, wherein theplurality of flexible members each includes an enlarged element at itsdistal end.